Method for protecting a specific region in a sample applied in preparing an ultra-thin specimen

Abstract

A method for protecting a specific region in the sample applied in preparing an ultra-thin specimen is disclosed. The method includes the steps of (a) forming a first concavity on a first side of the specific region by a focus ion beam (FIB) technique, (b) forming a second concavity on a second side of the specific region opposite to the first side by the focus ion beam technique, (c) filling the first concavity and the second concavity with a first metallic packing and a second metallic packing respectively, and (d) forming a third metallic packing on the specific region and extending to connecting with the first metallic packing and the second metallic packing to define a protecting device for protecting the specific region.

What is claim is:  
     
       1. A method for protecting a specific region in a sample applied in preparing an ultra-thin specimen to be observed by a microscope, comprising steps of: 
       (a) forming a first parallelepiped-like concavity on a first side of said specific region by a focus ion beam (FIB) technique;  
       (b) forming a second parallelepiped-like concavity on a second side of said specific region opposite to said first side by said focus ion beam technique;  
       (c) filling said first concavity and said second concavity with a first metallic packing and a second metallic packing respectively; and  
       (d) forming a third metallic packing over said specific region, said first metallic packing and said second metallic packing directly to define a protecting device for protecting said specific region.  
     
     
       2. The method according to  claim 1  wherein said third metallic packing has a first end connecting with said first metallic packing and a second end connecting with said second metallic packing to form said protecting device. 
     
     
       3. The method according to  claim 1  wherein said third metallic packing has a first end protruding beyond said first metallic packing and a second end connecting with said second metallic packing to form said protecting device. 
     
     
       4. The method according to  claim 1  wherein said third metallic packing has a first end protruding beyond said first metallic packing and a second end protruding beyond said second metallic packing to form said protecting device. 
     
     
       5. The method according to  claim 1  wherein said step (c) is executed by a sputtering technique. 
     
     
       6. The method according to  claim 1  wherein said microscope is one selected from the group consisting of an optical microscope (OM), a transmission electron microscope (TEM), and a scanning electron microscope (SEM). 
     
     
       7. The method according to  claim 1  wherein each of said concavities has a length and width ranging from 1 to 1.5 μm and a depth ranging from 2 to 3 μm. 
     
     
       8. The method according to  claim 1  wherein each of said metallic packings is made of one selected from Platinum (Pt) and Tungsten (W). 
     
     
       9. The method according to  claim 1  wherein the distance between said first concavity and said second concavity is about 5 μm. 
     
     
       10. The method according to  claim 1  wherein said ultra-thin specimen has a thickness of about 0.2 μm. 
     
     
       11. The method according to  claim 1  wherein said specific region has a length of about 5 μm and a width of about 0.2 μm. 
     
     
       12. The method according to  claim 1  wherein after said step (c), said method further includes a step of forming a third concavity on said first side of said specific region adjacent to said first concavity and then filling said third concavity with a fourth metallic packing. 
     
     
       13. The method according to  claim 5  wherein said third metallic packing is extending to connect with said first, said second and said fourth metallic packing to form said protecting device. 
     
     
       14. The method according to  claim 1  wherein after said step (d), said method further includes a step of (d1) forming a fourth concavity on a third side of said specific region. 
     
     
       15. The method according to  claim 7  wherein after said step (d1), said method further includes a step of (d2) forming a fifth concavity on a fourth side of said specific region opposite to said third side. 
     
     
       16. The method according to  claim 1  wherein after said step (d), said method further includes a step of (e) polishing one side of said sample with a higher polishing rate till said protecting device is partially polished. 
     
     
       17. The method according to  claim 9  wherein after said step (e), said method further includes a step of (f) polishing said one side of said sample with a lower polishing rate till said protecting device is completely exposed. 
     
     
       18. The method according to  claim 10  wherein after said step (f), said method further includes a step of (g) stopping polishing said one side of said sample and then polishing the other side of said sample opposite to said one side. 
     
     
       19. A method for protecting a specific region in a sample applied in preparing an ultra-thin specimen to be observed by a microscope, comprising steps of: 
       (a) forming a first parallelepiped-like concavity on a first side of said specific region by a focus ion beam (FIB) technique;  
       (b) forming a second parallelepiped-like concavity on a second side of said specific region opposite to said first side by said focus ion beam technique;  
       (c) filling said first concavity and said second concavity with a first metallic packing and a second metallic packing respectively; and  
       (d) forming a third metallic packing on said specific region directly, wherein said third metallic packing has a first end surface connecting with an inner surface of said first metallic packing and a second end surface connecting with an inner surface of said second metallic packing to define a protecting device for protecting said specific region.